Tales of a Shining Sword

Eunho, the strongest in the youkai realm! He gained the chance to become a human being after losing the woman he loved and killing countless youkai. After passing the gate of reincarnation by accumulating merit for a thousand years to abandon his immortal body... He became a human being, held a sword, and learned martial arts for the first time. But this is very... easy? (Source: Kakao Entertainment, translated)